CngAsnFormatter.cs

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using System;
using System.Buffers;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
 
namespace Internal.Cryptography;
 
internal sealed class CngAsnFormatter : AsnFormatter
{
    protected unsafe override string FormatNative(Oid oid, byte[] rawData, bool multiLine)
    {
        string s = string.Empty;
        if (oid != null && oid.Value != null)
        {
            s = oid.Value;
        }
        int dwFormatStrType = (multiLine ? 1 : 0);
        int pcbFormat = 0;
        IntPtr intPtr = Marshal.StringToHGlobalAnsi(s);
        char[] array = null;
        try
        {
            if (global::Interop.Crypt32.CryptFormatObject(1, 0, dwFormatStrType, IntPtr.Zero, (byte*)(void*)intPtr, rawData, rawData.Length, null, ref pcbFormat))
            {
                int num = (pcbFormat + 1) / 2;
                Span<char> span = ((num > 256) ? ((Span<char>)(array = ArrayPool<char>.Shared.Rent(num))) : stackalloc char[256]);
                Span<char> span2 = span;
                fixed (char* ptr = span2)
                {
                    if (global::Interop.Crypt32.CryptFormatObject(1, 0, dwFormatStrType, IntPtr.Zero, (byte*)(void*)intPtr, rawData, rawData.Length, ptr, ref pcbFormat))
                    {
                        return new string(ptr);
                    }
                }
            }
        }
        finally
        {
            Marshal.FreeHGlobal(intPtr);
            if (array != null)
            {
                ArrayPool<char>.Shared.Return(array);
            }
        }
        return null;
    }
}